Study On Non-enzyme Glucose Sensor Modified By Pt-Pb Nanoflowers

The electrochemical glucose biosensor is the most important method for the detection of glucose due to high selectivity, rapid response and convenience. In recent years, developing new glucose sensor was widely concerned in order to provide more effective methods of testing blood glucose for diabetics because of the increasing incidence of diabetes.Although enzyme sensor detection usually shows good selectivity and high sensitivity, the enzyme is easily denatured during its immobilization procedure because of the intrinsic stability of enzyme, which leads to the lack of stability.Therefore, the development of implantable glucose biosensor and nonenzymatic glucose biosensor is an active research area for the glucose analysis. Nanoparticles with strong adsorption capacity, fast catalytic efficiency, and good biological compatibility can be used as modified materials of electrode, because they possess lots of excellent properties, such as surface effect and volume effect. So the nanoparticles modified electrode shows promising applications for the biosensor construction. Therefore, in this paper, we reported a non-enzymatic electrochemical glucose sensor based on three-dimensional Pt-Pb flower-like nanostructures which were synthesized by electrochemical deposition. SEM images, TEM images and XPS results confirmed the formation of 3D Pt-Pb nanoflower nanostructures. The electrochemical tests showed that the Pt-Pb nanoflower-like particles modified electrode possess a large electroactive surface area and high electrocatalysis activity. Meanwhile, the non-enzyme biosensor constructed by it has a good stability and selectivity. The linear detection range of glucose was from 1 to 12 mM. The response sensitiviyt is 10.69μA/mM (n= 7) with a correlation coefficient of 0.9997, the detection limitation is 4μM (S/N= 3). Moreover, this 3D Pt-Pb nanoflower electrode wasn't serious effected by the temperature during the process of catalyzing glucose. The response current increased with a rise of temperature, and at last tend to be steady. Therefore, it will be more promising for 3D Pt-Pb nanoflowers electrode to construct non-enzyme biosensor than the traditional enzyme electrode.The present thesis was the first attempt to use a stainless steel needle electrode (SSN electrode) with a diameter of 0.35 mm as a substrate electrode. Pt-Pb nanoparticles were used to immobilizie the glucose enzyme to overcome the drawbacks of the small area of SSN electrode. A implantable glucose biosensor was constructed by codeposition chitosan (CS) / glucose oxidase (GOD) via electroreduction of benzoquinone. In the optimal experimental conditions, the sensor built by GOD-CS/Pt-Pb/SSN electrode showed good integrated performances, the linear detection range of glucose was from 0.03 to 9 mM with the response sensitivity is 0.44847μA/mM (R= 0.9994, n= 11), the steady-state current response time is 15 s and detection limitation is 0.17 mM (S/N= 3), the Michaelis constant ( ) value is calculated to 4.9837 mM.